Present communication techniques using wireless communication including radiofrequency transmissions (RF) raise security concerns because transmissions using RF can be easily intercepted, in part because of the fact that RF signals are designed to radiate signals in all directions. Second, radiofrequency transmissions may be regulated by the Federal Communications Commission (FCC) which may control the frequencies that may be used for RF transmission. Third, RF by its very nature is susceptible to interference and produces noise.
In contrast to RF communications, light sources used for communication are extremely secure due to the fact that they are focused within a narrow beam, requiring the placement of equipment within the beam itself for interception. Also, because the visible spectrum is not regulated by the FCC, light sources can be used for communications purposes without the need of a license. Light sources are also not susceptible to interference nor do they produce noise that can interfere with other devices.
Light emitting diodes (LEDs) may be used as light sources to attempt data transmission, as described in U.S. Pat. Nos. 6,879,263 and 7,046,160, the entire contents of each being expressly incorporated herein by reference. LEDs have a quick response to “ON” and “OFF” signals, as compared to the longer warm-up and response times associated with fluorescent lighting, for example. LEDs are efficient in the production of light, as measured in lumens per watt. Recent developments in LED technology, such as high brightness blue LEDs, have paved the way for white LEDs, which have made LEDs a practical alternative to conventional light sources. As such, LED technology provides a practical opportunity to combine lighting and communication. This combination of lighting and communication allows ubiquitous light sources such as street lights, home lighting, and office building lighting, for example, to be converted to, or supplemented with, LED technology to provide for communications while simultaneously producing light for illumination purposes.
In addition to use as general lighting, LEDs can be used in networking applications. In any network, a variety of client devices will communicate with one or more host devices. The host may provide connection to a Local Area Network (LAN), sometimes referred to as an Intranet, owing to the common use of such a network entirely within an office space, building, or business. The host may additionally or alternatively provide connection to a Wide Area Network (WAN), commonly describing a network coupling widely separated physical locations which are connected together through any suitable connection, including for exemplary purposes but not solely limited thereto such means as fiber optic links, T1 lines, Radio Frequency (RF) links including cellular telecommunications links, satellite connections, DSL connections, or even Internet connections. Generally, where more public means such as the Internet are used, secured access will commonly separate the WAN from general Internet traffic. The host may further provide access to the Internet.
A variety of client devices have heretofore been enabled to connect to host devices. Such client devices may commonly include computing devices of all sorts, ranging from hand-held devices such as Personal Digital Assistants (PDAs) to massive mainframe computers, and including Personal Computers (PCs). However, over time many more devices have been enabled for connection to network hosts, including for exemplary purposes printers, network storage devices, cameras, other security and safety devices, appliances, HVAC systems, manufacturing machinery, and so forth. Essentially, any device which incorporates or can be made to incorporate sufficient electronic circuitry may be so linked as a client to a host.
Existing client devices are designed to connect to host network access points through wired connections, like copper wire, for example, fiber optic connections, or as wireless connections, such as wireless routers. In the case of a wired system, whether through simple wire, twisted wire, co-axial cable, fiber optics or other line or link, the host and client are tethered together through this physical communications channel. The tether, as may be appreciated, limits movement of the client relative to the host, is often unsightly and hard to contain in a workspace, and so may even be or become a tripping hazard. In addition, electrical connectors such as jacks must be provided, and these connectors necessarily limit the number of access points and locations. The installation of connectors defaces walls, sometimes rendering them unsuitable for a particular desired application, and yet they add undesirable installation expense, whether during new construction or in retrofitting an existing building structure.
In contrast, in the case of wireless routers, an RF signal replaces the physical communications channel with a radio channel. This advantageously eliminates the wire or fiber tether between client and host. Instead, client devices in a wireless system try through various broadcasts and signal receptions to find an access point that will have adequate transmission and reception, generally within a certain signal range which may range from a few meters to as many as several tens of meters. The systems are programmed to bridge from a host access point to various client devices through known exchanges of information, commonly described as communications protocols or handshakes. Depending upon the communications channel, a variety of client connection devices are utilized such as PCMCIA or PC cards, serial ports, parallel ports, SIMM cards, USB connectors, Ethernet cards or connectors, firewire interfaces, Bluetooth compatible devices, infrared/IrDA devices, and other known or similar components.
The security of these prior art wireless devices may be compromised in that they are vulnerable to unauthorized access or interception, and the interception may be from a significant distance, extending often well beyond physical building and property boundaries. Moreover, reliability can be hindered by interference from an appliance such as a microwave oven.
The art referred to and/or described above is not intended to constitute an admission that any patent, publication or other information referred to herein is “prior art” with respect to this invention. In addition, this section should not be construed to mean that a search has been made or that no other pertinent information as defined in 37 C.F.R. §1.56(a) exists.
All U.S. patents and applications and all other published documents mentioned anywhere in this application are incorporated herein by reference in their entirety.
Without limiting the scope of the invention, a brief summary of some of the claimed embodiments of the invention is set forth below. Additional details of the summarized embodiments of the invention and/or additional embodiments of the invention may be found in the Detailed Description of the Invention below.
A brief abstract of the technical disclosure in the specification is provided for the purposes of complying with 37 C.F.R. §1.72.